Hi i am after some quick help please

My son is due for his 18 month immunisations this morning at 9.30,
he has woken up extremely upset and subsequently filled a nappy (well over filled and filled his pyjamas also) with dioreahh. (sp)

I am torn as to whether to have the jab done. On one hand, he must feel like crap, i am treating it with lots of fluids and panadol to bring his very very slight tempreture down.

Should i still have them done? on one hand he does normally get a little grizzly after his jabs, so would i be making it worse for the poor little fella? or should i jsut get it all over and done with. i dont want him feeling like poop, then 2 days later getting the jabs and feeling like poop again! should i just get all the yucky feelings that he is going to go through over and doen with? or delay it a bit????